Wont connect to multiplayer. Please help.

Well i’ve tried other games, so my Live Gold isn’t in question but I can’t seem to connect to other players. I keep being told to fix my multiplayer privileges, but my multiplayer connection is fine and i have an open Nat type. Anyone else experiencing this problem?

I usually have trouble first thing in the morning, EST, but around 10:00am I have better luck. I think the population is going down.